Extensive work is being carried out on zeolites and alkaline earth metal silicates compared to transition metal silicates.
In relation to transition metal silicates use for decontamination, Dodwell et al (U.S. Pat. No. 5,053,139, 1991) prepared transition metal silicates such as titanium and tin silicates, comprising cation exchangers, to remove heavy metals such as lead, cadmium, zinc, chromium and arsenic. When these metal silicates were failed to reduce the metal pollutant concentration, these metal silicates comprising with cation exchangers were prepared to reduce the metal pollutant concentration to required level. Although in patent claims, it was not mentioned about zirconium silicate (U.S. Pat. No. 5,053,139, 1991) but in the description (example 14) it was mentioned about zirconium silicate preparation along with cation exchanger, and the failure of zirconium silicate ion exchanger to reduce metal pollutant concentration in treated water.
It was observed that tin and titanium silicates failed to decontaminate coliform bacteria in drinking water when they were tested in our laboratory.
In the transition metals, anti-microbial metals such as silver, copper, zinc and manganese were well known and silicates of these metals were not studied in detail for the relation between function (such as decontamination, disinfection and microbicidal properties) and structural composition.
Copper silicates were known from 1936 (GB 442664) for agricultural or horticultural pest control and these copper silicates were synthesized by heating an aqueous suspension of finely divided hydrated silica with substantially insoluble basic copper compounds in alkaline conditions at high temperature.
The synthesis of various types of copper silicates based on the functional property was not studied among these reports or observations.
Many copper salts were formulated for use as agricultural pesticides and copper silicates do not gain much importance among them. Copper alumino silicates were mixed with antibiotics to obtain synergism between copper compounds and antibiotics (GB 788668).
Present invention is aimed to synthesize functional transition metal silicates of the required structural composition for targeted activities such as decontamination, disinfection and microbicidal properties etc. Another objective of the present invention is to invent novel immobilized functional transition metal silicates.